How Restrictive Is Your Diet?

By Matt Fitzgerald

Published Oct 21, 2013

Updated Oct 21, 2013 at 6:37 PM UTC

In the metrics that matter, a simple “high-quality” diet is best.

There are lots of different health-based diets out there. They can be distinguished from one another in various ways. Perhaps the two most important variables to consider when choosing a healthy diet to follow are research-proven health benefits and restrictiveness.

The very point of a health-based diet is its health benefits, of course. Proponents of each specific diet will, naturally, argue that theirs offers the greatest number and degree of health benefits. But you can’t take their word for it. You have to look at what real science says about it.

Some diets are more restrictive than others. That is, some have longer lists of prohibited foods than others. As a general rule, the more restrictive a diet is, the more difficult it is to sustain. Again, proponents of each specific diet will present themselves as living proof that it’s sustainable, but what’s sustainable for one person might not be for another.

Let’s look at the proven health benefits and restrictiveness of various diets.

Raw Food

The raw food diet is the most restrictive diet I know of. It consists of nothing but raw plant foods. If the only things you like to eat are fresh fruits, juices, nuts, seeds, salads, raw carrots and such, you’ll do just fine on this diet. Otherwise, it will probably drive you crazy.

Still, the raw food diet might be worth it if were significantly healthier than a slightly less restrictive diet, such as a vegan diet. Is it? No. For example, a recent study by Dutch researchers found that people who ate larger amounts of fruits and vegetables had a lower risk of heart disease regardless of whether the preponderance of those fruits and vegetables were raw or processed.

Vegan

As you know, vegans consume only plant foods. Not only are meat and fish off limits for vegans, but also eggs, dairy, honey, gelatin, and any and all other foods that involve animals in any way. It’s a very restrictive diet, but at least you can eat your spinach cooked.

Slightly more sustainable than strict veganism for the average person is a lacto-ovo vegetarian diet, which allows egg and dairy consumption. But are lacto-ovo vegetarians less healthy than vegans? In some ways yes, in others now. Studies have shown that vegans tend to be leaner than lacto-ovo vegetarians, but they also have lower bone mineral density and less muscle mass in relation to bodyweight, which is less desirable for athletes. Overall, it’s a wash.

Paleo Diet

While the Paleo Diet and other ancestral-type diets allow meat and fish consumption, they are more restrictive than the typical vegetarian diet because they don’t permit grains to be eaten, and grain-based foods are in fact the most abundantly eaten foods in the modern diet. Dairy products are also forbidden in ancestral diets, on the grounds that, like grains, our Paleolithic ancestors did not eat them. (Too bas this isn’t true. Recent evidence suggests some humans ate grains as long as 100,000 years ago.)

Is the Paleo Diet healthier than a simple “high-quality” diet in which no food types are forbidden, only “low-quality” foods of each type (e.g. processed grains vs. whole grains)? No. For example, a recent study out of the Harvard School of Public Health found that men and women who ate more than two servings of brown rice per week had a lower-than-average risk for type 2 diabetes, while those who ate five or more servings of white rice per week had an above-average risk for the disease.

In other words, whole grains are better than none at all. Other research suggests that, similarly, eating low-fat dairy products is better than eating none at all.

Vegetarian

As mentioned above, lacto-ovo vegetarians can eat everything except meat and fish. Given the quality and variety of mock meat products available these days, it’s a fairly sustainable diet. It’s still more restrictive than an omnivorous “high-quality” diet, however, and the available research suggests that it is not healthier than such a diet.

For example, a 2006 review of the literature reported that “several prospective studies showed no significant differences in the mortality caused by colorectal, stomach, lung, prostate or breast cancers and stroke between vegetarians and ‘health-conscious’ non-vegetarians.”

High-Quality Diet

A high-quality diet is a diet in which all food types are allowed, but an effort is made to avoid specific “low-quality” foods of all types and to eat “high-quality” foods of all types. For example, the Diet Quality Score system I present in Racing Weight categorizes fruits and vegetables, whole grains, low-fat dairy products, and essential fats as high-quality foods and refined grains, sweets, fried foods, whole-milk dairy products, and fatty proteins as “low-quality” foods.

We have already seen that a high-quality diet is just as healthy as any more restrictive health diet. Are high-quality diets healthier than “anything goes” diets—that is, the typical American diet? You bet it they are. For example, in a 2003 study by Swedish researchers, the diets of more than 58,000 women were analyzed for the variety of healthy and unhealthy foods they contained. It was discovered that those women who ate the greatest variety of healthy foods had the lowest mortality rate over a 10-year period, while those who ate the greatest variety of unhealthy foods had the highest mortality rate.

Anything Goes

Most people are on the anything goes diet. The average American diet is very low in fruit and vegetables and very high in sugar, refined grains, and fatty proteins. Literally thousands of studies have demonstrated that this diet makes people fatter and more likely to develop various diseases than just about any more restrictive diet.

And The Winner Is…

When health-based diets are analyzed in terms of their proven health benefits and their restrictiveness, the high-quality diet emerges as the clear best choice. It is just as healthy as the most restrictive diet while being far more sustainable for the average person. The only reason to be a raw foodist, vegan, vegetarian, or ancestral eater instead of a high-quality diet follower is personal preference.